Warming up bottle in the microwave

Is this bad? I remember warming up the water in the microwave 6 yr ago when my DS was a baby, but now I'm considering on getting a bottle warmer. Although I'm not sure if I should just do it in the MW and save $ and time.

I fed my LO room temp bottles from the start, if it has been in the fridge is might nuke it for 10 seconds to take the chill out but that's it. we had a bottle warmed, but I never used it, my kid wouldn't wait that long for a warm bottle. In the summer, we did give it to him a little cool still, but he was 7 months.

We were told to use boiled water for the first few months, so we always had a full kettle that we would let cool off, if I was feeling fancy, I would turn it on for a minute to re warm the water so it wasn't stone cold, but that's about it.

Don't put the nipple in the microwave though, it degrades it and it can burn the baby